This is most likely a tech support scam, not a real Microsoft lock on the PC.
What to do now:
- Do not call any phone number shown in the pop-up or message.
- Do not enter any username, password, or payment information.
- Try to close the browser or pop-up:
- Press Ctrl + Shift + Esc to open Task Manager.
- Find the browser process such as Microsoft Edge.
- Select it and choose End task.
- If that does not work, try Alt + F4 to close the browser window.
- If the screen still cannot be closed, restart the computer.
- If the browser asks to Restore tabs after reopening, choose No so the scam page does not reopen.
Important facts:
- Microsoft error and warning messages do not include phone numbers.
- Microsoft does not make unsolicited phone calls to say there is a problem with a device.
- If a pop-up says shutting down will cause data loss or demands a call, that is a common scam tactic.
If help is still needed from Microsoft, use the official support entry points:
- Get Help on the web
- Get Help in Windows